Eclipses

Essential Questions: Can you describe how the positions of the Sun, Moon, and Earth determine the type of eclipse? Can you model how the shadow cast in an eclipse causes partial and total eclipses?

Eclipses Eclipse The total or partial obscuring of the sun or moon by the moon or Earth’s shadow is an eclipse Types: solar and lunar © KeslerScience.com

Solar Eclipses Occurs when the Moon passes between the Earth and the Sun totally or partially obscuring Earth’s view of the sun The moon is in the new moon phase during a solar eclipse The moon casts a shadow on part of the Earth. © KeslerScience.com

Lunar Eclipses Occurs when the Earth passes between the Moon and the Sun. The Earth casts a shadow on the Moon blocking all or a portion of it. The moon is in the full moon phase during a lunar eclipse Occurs at night © KeslerScience.com

Total and Partial Solar Eclipse A total solar eclipse occurs when the moon blocks out all the sun’s light. Total eclipses happen at least once every couple years, but are only seen in a specific region (‘right place, right time’) Most last 7.5 minutes (when the sun is completely covered by the moon) © KeslerScience.com

Total and Partial Solar Eclipse A partial solar eclipse occurs when the moon blocks out only a part of the sun. © KeslerScience.com

Perigee Apogee Visual appearance of the moon at its closest and furthest points from Earth. the point in the orbit of the moon at which it is furthest from the earth. the point in the orbit of the moon at which it is closest to the earth.

Eclipses Annular Eclipse When the Moon is at its furthest point in orbit (apogee) Its shape will not cover the Sun completely. This is when you can see a thin ring of light emerging from the outside rim of the moon. © KeslerScience.com

Total and Partial Lunar Eclipse A total lunar eclipse occurs when the moon completely passes into the darkest part (umbra) of Earth’s shadow Only occurs during full moon phase Occurs at night © KeslerScience.com

Total and Partial Lunar Eclipse A partial lunar eclipse occurs when the moon passes into the lightest part (penumbra) of Earth’s shadow. Occurs only at Full moon phase Occurs at night © KeslerScience.com

Umbra Umbra/Penumbra The darkest part of a shadow is the umbra The cone-shaped region of full shadow cast by Earth and the Moon during an eclipse. (This is where total eclipses occurr, whether it’s solar or lunar) © KeslerScience.com

Umbra/Penumbra Penumbra The area of partial shadow surrounding the total shadow cast in an eclipse is the penumbra © KeslerScience.com

You can see a TOTAL solar eclipse when you are…. In the umbra shadow... When the umbra from the Moons shadow touches Earth, you have a total solar eclipse. Point C in the diagram (this is why only very small regions at a time can see a total solar eclipse. The rest of the world sees something else...) A total solar eclipse. © KeslerScience.com

You can see a PARTIAL solar eclipse when you are ... In the penumbra shadow When the penumbra of the Moon’s shadow touches Earth you have a partial solar eclipse Point B in the diagram (While one very small part of the world sees a total solar eclipse (point c) , if you are still close enough in the penumbra shadow(point b and a), you will see at least a partial solar eclipse) A partial solar eclipse © KeslerScience.com

How about the total and partial lunar eclipses? Same rules! You see a total lunar eclipse (aka ‘red’ moon’) if the moon is in the umbra of the Earth’s shadow (take a close look at the diagram). You see this: © KeslerScience.com

Penumbra/Partial Lunar Eclipse When the penumbra of the Earth’s shadow touches the Moon you have a partial/penumbral lunar eclipse © KeslerScience.com

Check for Understanding Can you… Describe the different types of eclipses? Model the differences between lunar and solar eclipses. Model umbra and penumbra in a solar/lunar eclipse. © KeslerScience.com